1. The Field of the Invention
The present invention relates generally to thermoplastic films and bags formed therefrom. More particularly, the present invention relates to thermoplastic films and bags including multiple layers and unique aesthetics.
2. Background and Relevant Art
Thermoplastic films are a common component in various commercial and consumer products. For example, grocery bags, trash bags, sacks, and packaging materials are products that are commonly made from thermoplastic films. Additionally, feminine hygiene products, baby diapers, adult incontinence products, and many other products include thermoplastic films to one extent or another.
The cost to produce products including thermoplastic film is directly related to the cost of the thermoplastic film. Recently the cost of thermoplastic materials has risen. In response, many manufacturers attempt to control manufacturing costs by decreasing the amount of thermoplastic material in a given product.
One way manufacturers may attempt to reduce production costs is to use thinner films or stretch the thermoplastic films, thereby increasing surface area and reducing the amount of thermoplastic film needed to produce a product of a given size. Unfortunately, stretched or otherwise thinner thermoplastic films can have undesirable properties. For example, thinner thermoplastic films are typically more transparent or translucent. Additionally, consumers commonly associate thinner films with weakness. Such consumers may feel that they are receiving less value for their money when purchasing products with thinner films; and thus, may be dissuaded to purchase thinner thermoplastic films.
To compensate for some deficiencies of thinner films, manufacturers may add colorants or voiding agents. Depending on how they are used, however, colorants and voiding agents can sometimes weaken the chemical bonds in the film, and create a still weaker film. Moreover, the use of certain colors in a film structure may present unique challenges, such as expensive. For example, metallic pigments, which are often thought of as indicating strength, are particularly expensive. As such, the cost of some pigments can counter any savings gained by the use of thinner films. Furthermore, even pigmented films commonly become less opaque upon stretching.
As such, manufacturers may be dissuaded to stretch a film or use thinner films despite the potential material savings. This is particularly the case when strength is an important feature in the thermoplastic product. For example, thermoplastic trash bags need to be puncture and tear resistant to avoid inadvertently spilling any contents during disposal. Consumers may be hesitant to purchase bags made from thinner films fearing that the bags will fail along the seams or other areas of the bag commonly subjected to stresses.
Accordingly, continued improvement is needed to address the unique problems associated with improving trash bags while conserving the use of expensive thermoplastic materials and pigments.